Autopsy 8: Dead Giveaway
The 'detectives of death' investigate another slate of bizarre cases, including: a twisted case of sibling sabotage; a mystery where saliva turned a suicide into a homicide; the story of a convicted rapist whose claims of innocence are taken seriously when his DNA turns up on a victim while he is in jail; and a 'final answer' to the question, 'Who was the Black Widow?'
Starring
Watch "Autopsy 8: Dead Giveaway" on Amazon released in 2002. It's a documentary and action & adventure movie, and has a rating of 7.8 out of 10 from Imdb which is usually fine for this kind of movie, and is currently only available for purchase or rent.